Diagnosing Granulomatous Inflammation of the Skin

OBJECTIVE: To determine the applicability of recognizing cellular reaction patterns in the cytologic diagnosis of granulomatous inflammation of the skin. STUDY DESIGN: Prospective. Two hundred seventeen cases of clinically suspected granulomatous dermatitis formed the data for this study. May-Grünwald-Giemsa, Ziehl-Neelsen, periodic acid-Schiff, silver impregnation and Gram staining methods were employed. RESULTS: Five cytomorphologic patterns of granulomatous inflammation were identified: epithelioid cell granulomas (77), histiocytic granulomas (20), epithelioid cell granulomas with polymorphous exudate (77), foreign body granulomas (3) and fat necrosis with granulomas (9). CONCLUSION: Correlating clinical presentation with cytomorphologic patterns often yields diagnostic information in the workup of granulomatous inflammation of the skin and frequently obviates the need for biopsy.